Encephalitis

Background

• Infection of brain parenchyma causing distinct neurologic abnormality
• Microbiology
  • HSV, HZV, EBV, CMV, rabies, arboviruses (West Nile, St. Louis equine)
• Pathophysiology
  • Gray matter is predominantly affected (cognitive / psychiatric signs, lethargy, seizure)

Clinical Features

1. New psychiatric symptoms (HSV)
2. Cognitive deficits
   1. Aphasia, amnesia, confusion
3. Seizure
4. Movement disorder (arboviruses)
5. Fever and meningeal signs are almost always present

Diagnosis

1. CT Head
   1. Medial temporal and inf frontal grey matter c/w HSV
2. LP
   1. Bloody tap c/w HSV

DDX

1. Meningitis
2. SAH
3. Lyme disease
4. Brain abscess
5. Bacterial endocarditis
6. Toxic / metabolic encephalopathy

Treatment

1. HSV encephalitis
   1. Acyclovir 10mg/kg q8hr
2. HZV encephalitis
   1. Acyclovir 10mg/kg q8hr
3. CMV encephalitis
   1. Ganciclovir 5mg/kg IV q12hr

Disposition

1. Admit

Source

Tintinalli